JPH01253623A - Torque measuring apparatus - Google Patents

Abstract

PURPOSE:To make strain generating plates thin, to make a measuring apparatus light and to improve measuring accuracy, by removing the central part of the disk of a wheel, overlapping and attaching two strain generating plates wherein many spoke-shaped strain generating pieces are formed, and constituting a Wheatstone bridge with strain gages which are attached to specified positions. CONSTITUTION:The central part of a disk 4 of a wheel 3 is cut. Two strain generating plates 7 and 8 are overlapped and attached through an adaptors 6. Many circular strain-generating-piece forming holes are provided on the specified circumferences of the strain generating plates 7 and 8. The strain generating pieces for torque are selected every other step in the turning direction. Strain generating pieces for side force are selected every three steps. Strain gages are attached to specified positions 9-12. A Wheatstone bridge for detecting torque/side force is constituted with these gages. The detection of the torque and the detection of the side force are performed independently at the same time. In this way, effect other than the torque acting on a vehicle can be neglected. Therefore, the strain generating plates can be made thin. The structure can be made simple and light. The torque can be measured accurately in the state close to the actual vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a torque measuring device, and more particularly to a torque measuring device that converts and measures torque acting on a wheel into an electrical quantity. (b) Conventional technology 1- Measuring the torque acting on the wheels of a vehicle such as an automobile
As a torque measuring device, for example, by forming a large number of holes on the virtual circumference of a disk-shaped strain plate with a predetermined radius, spoke-shaped strain pieces extending in the radial direction of these holes are formed. A strain gauge is attached to a strain plate, and the strain plate fixed perpendicularly to the axis of a drive shaft is fixed to a disc of a wheel. Several torque measuring devices have already been put into practical use, which convert the torque acting on a wheel into an electrical quantity using a bridge. An example of this is a torque measuring device proposed in Japanese Patent Publication No. 60-3453. However, this conventional torque measuring device has the following problems. First, in order to suppress the influence of the force (side force) in the axial direction of the drive shaft that acts as a disturbance, the thickness of the strain-generating piece in the axial direction is set to be sufficiently large compared to the width in the circumferential direction. However, if this is done, the thickness of the strain plate increases and the weight increases significantly compared to the normal wheel weight (unsprung weight), which has a negative effect on the 1~1-lux measurement. . Second, the strain gauge that converts torque into electrical quantity is placed outward from the center of the strain plate, but this placement position cannot be said to be the optimal position for torque detection. Therefore, depending on the width dimension of the strain-generating piece, the required output may not be obtained. Third, when a torque measuring device is attached to a wheel, a proper wheel offset cannot be ensured, which is a fatal flaw when torque is measured under conditions where offset changes give errors to the measurement. . (c) Purpose The present invention was made in view of the above-mentioned circumstances, and its purpose is to substantially eliminate the influence of acting forces other than 1 to 1 lux, especially side force and wheel load, while having a simple configuration. The total thickness of the strain plate can be made much thinner than conventional ones, which makes it possible to reduce the weight and improve measurement accuracy.Moreover, it maintains the normal offset. The object of the present invention is to provide a torque measuring device that obtains the desired torque. (d) Structure In order to achieve the above-mentioned object, the present invention provides a 1-herk measuring device that converts and measures 1 to 1 lux acting on a wheel into an electrical quantity, in which a large circular hole is formed in the center of the disk. a mounting adapter that is fitted into the circular hole of the wheel and firmly attached to the wheel while maintaining the same offset as the regular wheel; By concentrically overlapping with the adapter and uniformly forming a number of holes divisible by at least 4 on a circumference of a predetermined radius, spoke-like strain-generating pieces extending radially between the adjacent holes are formed. A J-th strain plate is formed in plurality, the thickness in the axial direction of the strain plate is larger than the minimum width in the radial direction, and the J-th strain plate is detachable from the drive shaft of the vehicle with a mounting bolt. Approximately disk-shaped,
At least a strain-generating piece is formed under the same conditions as the strain-generating piece of the first strain-generating plate, is overlapped concentrically with the first strain-generating plate, and is arranged in the inner vicinity and outside of the strain-generating plate. A second strain plate is firmly fixed to the first strain plate with bolts in the vicinity, and the holes are paired with predetermined strain pieces of the first and second strain plates in between. A strain gauge is attached to a first attachment surface on one side and a second attachment surface on the other side, and the strain gauge attached to the first attachment surface forming one of the pair is Circuits are connected to the opposing first and second bridge sides, respectively, and strain gauges attached to the second attachment surface forming the other of the two pairs are connected to the strain gauges adjacent to the first and second bridge sides, respectively. Third
A Wheatstone bridge for torque detection is constructed by connecting circuits to the and fourth bridge sides, respectively. DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a partially cutaway side view showing the overall configuration of the torque measuring device according to the present invention, and FIG. Figure 3 is a side view showing the external configuration with a slightly simplified and partially broken view.
FIG. 2 is a front view of FIG. 1 (however, wheels are omitted). In Figures 1 to 3, 1 is a drive shaft as a rotating shaft for driving a wheel, 2 is a caliper 13 consisting of a brake drum, etc., for the above-mentioned wheel (however, the tire part is omitted), and 3a is a rim of this wheel 3. , 4 is a disc of the wheel 3 that is integrated with this rim 3a by welding, and 4 is indicated by a two-dot chain line in FIG.
Although a will be described in detail later, in this example, the disk 4 has already been hollowed out into a large circular shape, and a cut portion that does not exist, 5 is an annular mounting adapter, and 6 is a portion that strengthens the mounting adapter 5 and the disk 4. a welded portion 7 and 8 are both substantially disk-shaped first and second strain plates;
9, 10 and 11.12 are provided on the first strain plate 7 and the second strain plate 8, respectively, and are designated as strain gauge attachment surfaces (hereinafter referred to as "strain gauge attachment surfaces") to which strain gauges (not shown) are attached. ), 13 is the first and second strain plate 7,
An annular space having a rectangular cross section is formed by combining the annular grooves formed in 8, 14 and 14a are communication holes bored in the second strain plate 8, and 15 and 15a communicate with the communication hole 14. A counterbore hole and a screw insertion hole for a hub bolt for fixing the first strain plate 7 to the drive shaft 1, a hole 16 for avoiding a protrusion on the end surface of the drive shaft 1, and a hole 17 communicating with the communication hole 14a. 18 is the terminal board, and 18a is a terminal chamber for storing the terminal board 18.
One of the terminals is shown as a representative; 18b is a screw for fixing the terminal plate 18 to the terminal chamber 17 of the first strain plate 7; 19 is the annular space 13, the communication hole 14, and the terminal; A wiring groove communicating with the chamber 17, 20 a connecting portion formed in the center of the second strain plate 8, 21 a wire collecting space bored in the center of the connecting portion 20, and 22 a wire collecting space 21. and a wiring nail hole that communicates with the terminal chamber 17 and the counterbore 6 15; 23 is a disc-shaped outer cover;
a is an insertion hole communicating with the communication hole 14, 24 is a disc-shaped inner cover that loosely fits into the mounting adapter 5, and 25 is the outer cover 23. 'Bolts 27 and 27a for concentrically and integrally connecting the first and second strain plates 7 and 8 to the mounting adapter 5 to form the detector 26 are connected to the first and second strain plates 7 and 8.
A bolt 28 connecting the second strain plates 7 and 8 indicates the axial center of the drive shaft 1, and 29 indicates the center of the wheel 3 in the axial direction. Further, 29a indicates the normal wheel position (offset). Reference numeral 30 denotes the detector 26, more specifically, a gear fixed concentrically with the connecting portion 20 of the second strain plate 8 to detect the speed, and 3'1 denotes the rotational speed of the gear 3o, that is, the wheel 3. A magnetic sensor 32 detects the rotation speed of the detector 26
A slip ring device 33 is a rotating part 33a which is concentrically and rotatably coupled to the gear 30.
is a slip ring provided on the outer periphery of this rotating part 33,
Reference numeral 34 designates an input/output terminal consisting of a waterproof connector for extracting the signal from a stationary portion against the rotation, and 35 represents a female threaded portion for attaching a support member (not shown) to prevent rotation of the slip ring device 32 itself. In the following drawings, the same members shown in FIGS. 1 to 3 are given the same reference numerals and redundant explanations will be omitted. 4 and 5 are diagrams showing the structure of the first strain plate 7 in detail, FIG. 4 is a front view, and FIG. 5 is a line A-A in FIG. 4.
' It is a sectional view in the direction of the arrow. In FIG. 4 and FIG. 5, 36 is a first strain plate 7 and a second strain plate 8 in order to accurately align the positions of the first strain plate 7 and the second strain plate 8.
two positioning pins planted on the periphery of the strain plate 70;
37 is drilled on the same radius, and 16 insertion holes are inserted through which the bolts 25 shown in Fig. 1 are inserted, and 38 and 39 are drilled in the circumferential direction at a radial position slightly inside of this insertion hole 37. An annular groove 19 with a concave cross section connects the annular groove 38 to the terminal chamber 1.
A wiring groove with a concave cross section communicating with 7, 40 is this annular groove 38
．． 32 as a number of holes evenly distributed inside 39
The constrictive mushroom forming holes 41 are formed by spokes having a minimum width S between the two adjacent holes of the constrictive mushroom forming holes 40 and having a thickness t between the annular grooves 38 and 39. It is a strain-sensitive piece having a shape, and is formed so that the thickness t is larger than the minimum width S. Reference numeral 42 denotes a torque straining piece selected every other one in the circumferential direction among the straining pieces 41, and 48 denotes a side force straining piece selected every third. Each strain-generating piece 41 has a surface that is visible from the clockwise direction and a surface that is visible from the counterclockwise direction, and in this example, the former will be referred to as the first attachment scheduled surface and the latter will be referred to as the second attachment scheduled surface. . Therefore, the attachment scheduled surfaces 9 and 10 shown in FIG. 1 are the first attachment scheduled surface 9 and the second attachment scheduled surface, respectively]-
It becomes 〇. Al. A2. A3. ..., A16 is each torque straining piece 42
Strain gauges 1 to 2 for detecting ruta, Bl, B2, attached to the first attachment scheduled surface. B3. ... B 1.6 is a strain gauge for torque detection attached to the second attached surface of each torque strain-generating piece 42, and El and F are the first attached strain gauges of the side-force strain-generating piece 43. A strain gauge for detecting side force attached perpendicularly to the scheduled surface (details will be described later), and B2 and F2 are strain gauges for detecting side force attached to the second scheduled surface in the same way,
Similarly, strain gauges with alphabetical letters E and F are placed on the first attachment plane for strain gauges with an odd number next to the letter, and strain gauges with an even number on the second attachment plane. El6 and B
Up to 16 are attached. Reference numerals 44 and 45 denote 16 screw holes which are equally distributed on a circumference having a predetermined diameter outwardly and inwardly with the annular groove 38 and 39 in between, respectively, and each having a female thread installed on the inner periphery. The bolts 27 and 27a shown in the figure are configured to be screwed together, respectively. 46 is a screw hole provided at the bottom of the terminal chamber 17 and screwed into the screw 18b for attaching the terminal plate 18 shown in FIG. 6 and 7 are drawings showing the structure of the second strain plate 8 in more detail, FIG. 6 is a front view, and FIG. 7 is a sectional view taken along the line B-B' in FIG. 6. It is. In FIGS. 6 and 7, 47 is a pin hole into which the positioning pin 36 is inserted, 48 is a hole bored at a position corresponding to the insertion hole 37 of the first strain plate 7, and the bolt 25 is bored in the same manner as above. The insertion holes 49 and 50 are annular grooves formed in substantially the same manner as the first strain plate 7, and the holes 49 and 50 are formed between the strain mushroom forming hole 40 of the first strain plate 7 and the passage. The strain mushroom forming holes 52, 53, and 54 formed in the strain plate 7 and the strain piece, the torque strain piece, and the side force strain piece formed between the first strain plate 7 and the passage, respectively, C1.゜C2,C
3,-, C16 and Di, D2. D3,...,D1
Similarly, strain gauges 6 and 12 for torque detection are attached to the first and second attachment surfaces of the torque strain piece 53, G] and H, respectively.
1, G2 and H2, . . . , G16 and H16 are also attached strain gauges in the same way as the strain gauges with English letters E and F on the first strain plate 7, and are attached to the side force strain plate 54. has been done. 55 and 56 are counterbore holes 55a and 56a, respectively.
57 is a mounting hole formed at a position corresponding to the screw holes 44 and 45 of the first strain plate 7 and through which the bolts 27 and 27a are inserted, respectively. This is a mounting hole through which a bolt 30a connecting the gear 30 shown in the figure is inserted. FIGS. 8 and 9 are enlarged cross-sectional views showing the attached state of the strain gauge, with the portions of the first intended attachment surface 9 and the second intended attachment surface 1o shown in FIG. 5 being representative, respectively. FIG. 9 shows the attached state of the strain gauge for torque detection, and FIG. 9 shows the attached state of the strain gauge for side force detection. In FIG. 8, 58 indicates the position of the minimum width S of each strain-generating piece 41, and in this example, it is the center of the strain-generating piece 41 that substantially coincides with the center of the strain-generating mushroom forming hole 40°51. 59 is the base of the strain gauge All, 60 is a strain receiving part (so-called gauge grid) for detecting the bending stress, 61
is a gauge tab, and 62 is a gauge lead. As can be seen from the figure, the strain receiving part 60 of the strain gauge A11 is located at the center 58.
The base 59 is attached to the first planned surface 9 so as to be located at the position where the maximum bending stress occurs, which is P inward from the base 59. The applicant has experimentally confirmed that the above position generates the maximum bending stress. In FIG. 9, reference numeral 63 indicates a pair of strain gauges E2.63 for detecting shear stress. The base of F2, 64 and 65 are respectively the strain receiving part (gauge grid) and the gauge lead of the strain gauge F2, and 66 and 67 are respectively the strain receiving part and the gauge lead of the strain gauge E2. Pair of strain gauges E2. F2 are attached on the center 58 so as to be substantially perpendicular to each other. FIG. 10 is a circuit diagram showing an embodiment of a torque detection bridge (Wheatstone bridge). In the figure, 68 to 71 are connection terminals of the bridge;
Reference numeral 72 denotes a series branch line in which strain gauges A1 to A8 attached to a portion corresponding to the half circumference of the first strain plate 7 are connected in series, and a portion corresponding to the half circumference of the second strain plate 8. The first side 73, in which the series branches to which attached strain gauges C1 to C8 are connected in series, are connected in parallel between the connection terminals 68 and 70, faces the first side 72, and Strain gauge A attached to the part corresponding to the remaining half circumference
A second side in which the series branches 9 to A16 and the series branches C9 to C16 are both connected in parallel between the connection terminals 69 and 71;
Both sides 74 and 75 are adjacent to the first side 72 and the second side 73 and are opposite to each other, and of these, 75 is a half circumference of the first strain plate 7 and the second strain plate 8, respectively. The third side 75 is formed by connecting the series branches of the strain gauges 81 to B8 and the series branches of D1 to D8 in parallel between the connecting terminals 68 and 71, and 75 is the first strain plate 7 and the second strain plate 7. Strain gauges 89 to B1 attached to parts corresponding to the remaining half circumference of the strain plate 8
6 and the series branches D9 to D16 are connected to the connection terminal 6.
This is the fourth side formed by connecting in parallel between 9.70 and 70. In this example, the connection terminals 68 and 69 are the output terminals of the bridge, and the connection terminals 70 and 71 are the bridge power input terminals. FIG. 11 is a circuit diagram showing an embodiment of a bridge for side force detection. In the figure, 76 to 79 are connection terminals of the bridge;
Reference numeral 80 denotes a part corresponding to the half circumference of the first strain plate 7, a series branch line to which the strain gauges E1 to E8 attached thereto are connected in series, and a part corresponding to the half circumference of the second strain plate 8. A first side 81 is opposite to this first side, and consists of a series branch line in which strain gauges 01 to G8 attached to the line are connected in parallel between the connection terminals 76 and 78. Series branches of strain gauges E9 to E16 attached to portions corresponding to the remaining half circumference of the above-mentioned half circumference of the strain plate 7.8 of No. 2 and 09
The second side 82, in which the series branches of ~G16 are connected in parallel between the connection terminals 79 and 77, is a strain gauge F1 for half the circumference of the first strain plate 7 and the second strain plate 8, respectively. ~F8
and the series branches of strain gauges H1 to H8 are connected in parallel between connection terminals 76° and 79.
is the strain gauge F corresponding to the remaining half circumference of this third side
The fourth side is formed by connecting the series branches of strain gauges H9 to H16 in parallel between the connection terminals 77 and 78. In this example, the connection terminals 76 and 77 are the output terminals of the bridge, and the connection terminals 78 and 79 are the bridge power input terminals. FIG. 12 is an enlarged plan view showing the vicinity of the torque strain-generating piece 41 having the first attachment surface 9 in an exaggerated manner in order to explain the torque detection operation. In the same figure, 84a and 84b are arrows indicating the acting direction of force and the acting direction of reaction force, 85 is the outer part of the torque straining piece 41, 86 is also the inner part, and 87 is, for example, the first
9 is a diagram showing the distribution of bending stress on the planned surface 9. FIG. 13 and 14 are schematic diagrams schematically showing FIG. 1 to explain the side force detection operation.
FIG. 4 is an enlarged schematic diagram showing a part of FIG. 13 in an exaggerated manner. In the figure, 88 is a tire constituting the wheel 3, 89 is the ground, 90 is an arrow indicating the direction of the side force, and 91 is a diagram showing the distribution of shear stress generated in the side force bending piece 43.54. be. The assembly procedure of this embodiment configured as described above will be briefly explained. First, the terminal plates 18 are respectively attached to the four terminal chambers 17 shown in FIG. 4 using screws 18b as shown in FIG. 1. Next, place the strain gauge in the position shown in Figures 4 and 6.
More specifically, for torque detection, the state shown in FIG.
The parts for side force detection are attached in the state shown in FIG. 9. These strain gauges are connected to the first strain plate 7 and the second strain plate 8 as shown in FIGS. 10 and 11.
For example, if we take the strain gauge A1-88 as a representative, the connections from A1 to A2, A
The respective gauge leads are connected in series from 2 to A3, and the connected gauge leads are made to run along the inside of the annular groove 38. Further, one gauge lead of the strain gauge A1 and one gauge lead of the strain gauge A8 are connected to a predetermined terminal ]-88 of the terminal chamber 17 along the nearest wiring groove 19, respectively. That is, the connection terminals 68 to 71 in FIG. 10 and the connection terminals 76 to 79 in FIG. 11 are respectively connected to predetermined ones of the 16 terminals 18a on the gold side. Meanwhile, the next processing of the wheel 3 is performed. That is, in the general wheels 3 on the market, as shown in FIG. 2, the disc 4 is integrally molded up to the cut portion 4a shown by the dashed line, so the cut portion 4a is cut into a large circular shape. Remove it, insert the mounting adapter 5 into the hole created by this,
The disk 4 and the mounting adapter 5 are firmly fixed together by welding at the welding portion 6. This secondary processing allows the regular offset (29a) to be maintained. Next, the first strain plate 7 and the second strain plate 8 are connected to each other by bolts 27.
．． Connect firmly at 27a. At this time, positioning pin 3
6 and the pin hole 47, the terminal chamber 17 and the communication hole 14. a and counterbore hole 15 and communication hole 1
Roughly, an annular space 13 is formed by the annular groove 38 of the first strain plate 7 and the annular groove 49 of the second strain plate 8, and the wiring of the first strain plate 7 The opening of the groove 19 is
A wiring hole is formed by closing the strain plate 8. Therefore, the strain gauges (bridges) arranged on the first strain plate 7 and the second strain plate 8 are connected and wired through the annular space co-3, the wiring groove 1-9, and the terminal chamber 17. . Next, the inner cover 24 is attached to the inside of the first strain plate 7 (on the drive shaft 1 side) to prevent foreign matter from entering the strain well forming hole 40 and adversely affecting the strain gauge. On the other hand, after attaching the magnetic sensor 31 to the slip ring device [32], the gear 30 and the rotating body 33 are connected.
The outer cover 23 is inserted into the end portion (above the drive shaft) and left in a loosely fitted state. Then, the lead wires (not shown) connected to each slip ring 33a are drawn out from inside the rotating body 33 to the wire collection space 21, and from there, the required number of wires are distributed to each terminal chamber 17 through the wiring nail hole 22, and then the gear 3
0 and the connecting portion 20 are connected with a bolt 30a. That is, here, the first strain plate 7, the second strain plate 8, the gear 30, and the slip ring device 32 are combined, and the outer cover 23 is loosely fitted between the second strain plate 8 and the gear 30. It is in a state of being Next, the outer cover 23 is rotated by hand to align the insertion hole 23'a with the terminal chamber 17, and the distributed lead wire is connected to the terminal 18a. Next, the outer cover 23 is rotated so that the insertion hole 23a fits into the counterbore hole], and the stacked first and second strain plates 7, 8 and the outer cover 23 are connected with the bolts 25. Tighten and connect to adapter 5. That is, at this stage, the wheel 3, the detector 26, the slip ring device 32, etc. are connected. Next, a hub bolt (not shown) is inserted into the insertion hole 23a, the communication hole 14, the counterbore hole, and the screw insertion hole 15a to connect the drive shaft 1 to the detector 26 (more specifically, the first strain plate). 7) and complete the assembly. The bridges for torque detection and side force detection have input/output terminals 34,
Connection terminals 70, 71 and 78.79 are connected to the bridge power supply via the slip ring device 32 and the lead wires, and connection terminals 68.69 and 76.77 are connected from the input/output terminal 34 to an external measuring device. shall be carried out. Next, the operation of this embodiment assembled in this way will be explained. First, the torque detection operation will be described. In FIGS. 4 and 6, it is assumed that the outer circumferential sides of the first and second strain plates 7 and 8 are fixed, and the inner circumferential sides are indicated by arrows 8 and 8.
It is assumed that the rotational force is applied in the clockwise direction shown in 4. The mode of deformation of the strain-generating piece 41 at this time is measured by strain gauge All
A case in which Bll and Bll are attached will be described based on FIG. 12 as a representative example. In response to the force in the direction of the arrow 84a, the first attachment surface 9 side of the inner portion 86 of the strain-generating piece 41 is compressed, and the opposite surface thereof is expanded. Therefore, strain gauge A11
The resistance value of strain gauge Bll decreases, and the resistance value of strain gauge Bll increases. That is, the strain gauges B1 to B16 attached to the first attached surface 9 of the first strain plate 7 and the second strain plate 8
and the resistance values of D1 to D16 increase, and the strain gauges A1 to A16 and C1 to C1 attached to the second attachment scheduled surface
6 resistance value decreases. In other words, in the bridge shown in Figure 10, the resistance value decreases on the first side and the second side, and the resistance value decreases on the third side.
The resistance values of the sides and the fourth side increase, and a detection current flows from the connection terminals 68 to 69. In addition, the rotational force 84
It goes without saying that if the direction of is reversed, the direction of the detection current will be reversed. Next, the removal of interference in this torque detection operation will be described. Firstly, the interference of the force in the axial direction of the drive shaft and the sagging side force can be reduced by making the thickness t sufficiently larger than the width S of the strain-generating piece 41.52. , strain gauges A1 to A16 for torque detection.
Bl~B16° C1~C16, Di~D16 are attached to the inner side where large bending stress is generated as shown in the diagram 87 of Fig. 12, and the sensitive axis of the strain gauge is attached as shown in Fig. 8. are selected in the orthogonal direction, where the influence of side force is least, and the first and second strain plates 7 and 8 are of a two-piece structure, reducing the total plate thickness while reducing the axial load. It is possible to increase the rigidity in the direction and axial direction, and as a result, the expansion and contraction of each strain-generating piece and the occurrence of bending in the axial direction due to axial loads and site forces are greatly suppressed. Since this is electrically canceled out by the distribution of strain gauges on each side of the torque detection bridge, the influence of side force ultimately becomes practically non-existent. Next, assume that a vertical force, ie, an axial load, is applied as shown by arrow V in FIGS. 4 and 6. To avoid complicating the explanation, we will introduce strain gauge A, which receives the largest amount of axial load.
15. B15 pair, A7°G7 pair and C15,G1
Pair of 5, G7. The C7 pair will be explained as a representative example. Strain gauge A7°B15. C7 and G15 expand, and conversely strain gauges B 7 , A 15 , D 7 , C1
5 is compressed. Therefore, the bridge in FIG.
The resistance increases on the side 72 and the fourth side 75, and the resistance decreases on the third side 74 and the second side 73, the potential between the connection terminals 68 and 69 does not change, and the axial load is canceled. Further, when receiving a force (wheel load) in the vertical direction V shown by arrow V, the strain-generating pieces 41 and 52 located above the horizontal line passing through the drive shaft 1 are expanded, but the strain-generating pieces 41 and 52 located below the horizontal line are extended. The strain-generating pieces 41 and 52 are compressed, and since the amount of expansion and the amount of compression are equal, the influence of vertical force is electrically canceled. Next, the side force detection operation will be described for reference. Assume that the drive shaft 1 receives a force in the direction of an arrow 90 as shown in FIG. It is assumed that the tires 88 do not slide on the ground 89. Shear stress is generated in the side force strain pieces 43, 54, and the shear stress is maximum near the center 58 as shown in the diagram 91. and strain gauge E2. Pairs of F2 and G2. Taking the pair H2 as a representative, strain gauge E2°G2 is compressed, strain gauge F2. , H2 expands. That is, overall, E1 to E 1.6 and G1 to G16 are compressed, F1 to F16 and 1 to 1 to
Hi 6 is extended. Therefore, in the side force detection bridge of FIG. 11, the resistance values of the first side 80 and the second side 81 decrease, and the resistance values of the third side 82 and the fourth side 83 increase. As a result, a detection current corresponding to the side force flows from the connection terminals 76 to 77. Next, we will discuss how to remove the influence of other forces. First, when each side force strain-generating piece 4-3.54 receives a rotational force in the direction shown by the arrow 84, the strain gauge E2. The pair F2 is both in extension, and the pair of strain gauges El, Fl on the opposite side is in compression. Similarly, G2. The pair of I(2 is expanded, and the pair of Gl, I-(1 is compressed. This can be seen in Figure 1-). On the first side 80, the pair of El and F2 and the pair of G1 and 02 are pair,
On the third side 82, strain gauges that decrease the resistance value and increase the resistance value are arranged alternately in each series branch on each side 80 to 83, such as the pair of Fl and F2, the pair of Hl and F2, etc. There is no change in the bridge as a whole, as they form pairs and cancel each other out within one of these pairs. In other words, the influence of the rotational force 84 is electrically canceled. Further, the influence of the wheel load in the vertical direction (2) is also canceled out within the pair, so there is no influence. Note that the gear 30 rotates as the wheel 3 rotates, and the gear 30 rotates as the wheel 3 rotates.
The magnetic sensor 3 senses the unevenness of the tooth of 0, and this is detected as a pulse number by a separately provided counter or the like to measure the rotational speed of the car @3. In this way, according to this embodiment, the first and second strain plates 7 and 8 have a two-plate structure, and each strain plate 7 and 8 has a two-plate structure.
32 lunate-forming holes 4 on the circumference with a predetermined diameter of
0,5] is formed by drilling a strain-generating piece 41. , 52, 1-luke strain plates 42.53 are selected every other in the circumferential direction, and side force strain plates 4.3 are selected every third.
．． Choose 54. A strain gauge for torque detection and a strain gauge for side force detection are respectively attached to the first attachment scheduled surfaces 9 and 11 and the second attachment scheduled surface 10.12 on the opposite side, respectively. Since the Wheatstone bridge for detecting 1 herc and the Wheatstone bridge for detecting side force are configured, there is an advantage that torque detection and side force detection can be performed simultaneously and independently. Since each side of both bridges is configured by series connection of strain gauges disposed on the second strain plates 7 and 8 for each half circumference, a large number of strain gauges on the input side and output side connected to each strain gauge are constructed. This has the advantage that the gauge leads and lead wires can be shortened as much as possible, and the connections and wiring can be extremely simplified. Regarding the torque detection operation, each strain-generating piece 4], 52
The thickness t is made larger than the width S by '', and the side force direction and the sensitive axis of the torque detection strain gauge (for example, A11) are attached in the orthogonal direction where the influence is least, and the first and second Since the strain plates 7 and 8 have a two-piece structure, there is an advantage that practically no interference from side force or wheel load occurs. In this respect as well, the bridge was constructed so that the strain gauges canceled each other's outputs.
It has the advantage of not being interfered with by wheel loads. In addition, by simply performing the primary processing of the wheel 3 without modifying the caliper 2, drive shaft 1, etc., the correct offset of the wheel 3 can be maintained even after the detector 26 is installed, and it can also be used when changing tires on other vehicles. It has the advantage that it can be easily installed in the same way. Further, by using the above-mentioned two-piece structure, there is an advantage that the rigidity can be increased while substantially reducing the weight with respect to the wheel load. In addition, since the strain gauge for torque detection (for example, A]1) is attached to the inner side of the center 58 of the circle connecting the centers of the lunar formation holes 40.5]-, the sensitivity of torque detection is improved. There is an advantage to doing so. Further, since the structure (shape) of both strain plates 7 and 8 is simple, there is an advantage that special machine tools are not required and they can be easily manufactured. Furthermore, since the side force detection operation is configured to detect shear force, there is an advantage that highly accurate side force can be measured without being affected by changes in the diameter of the wheel. In addition, side force strain gauges (for example, El, Fl, G1, Hl) attached to the first attachment plane and strain gauges (for example, F2.
F2 and G2. H2) is configured to form a pair on each side of the bridge, which has the advantage that the effects of rotational force, wheel load, and horizontal force can all be canceled out within the pair, and their interference can be eliminated. . Further, since the rotational speed can be independently detected simultaneously with the torque detection and the side force detection by the gear 30 and the magnetic sensor 31, there is an advantage that the correlation with the speed can be accurately grasped. It should be noted that the present invention is not limited to the above-described embodiments, and can be modified in various ways without departing from the spirit thereof. For example, the number of lunate-forming holes 40.51 is not limited to 32, and may be changed as appropriate as long as the number is divisible by 4. In addition, the torque straining pieces 42.53 may be all of the straining pieces 41.52 instead of selecting every other one in the circumferential direction, and if the smoothness of the output signal can be maintained,
Conversely, you may choose every second. Further, the side force straining pieces 43, 54 may not be selected every third in the circumferential direction, but may be every second or fourth. In addition, the lunar formation hole 40.51 is not limited to a circular hole,
If there are no processing problems, a square hole, an oblong hole, or a fan-shaped hole may be used. (e) Effects As can be seen from the detailed description, according to the present invention, a wheel with simple perforations, a mounting adapter with a properly set offset, and a large number of strain-generating pieces are provided. The strain gauge is composed of first and second strain plates formed with the strain plate and a strain gauge attached to the portion of the strain plate where the maximum bending stress occurs, so the structure is simple and the strain gauge acts on the wheel. The effects of side forces and axial loads other than torque can be practically eliminated, and in particular, the total thickness of the strain plate can be reduced.
The walls can be made significantly thinner than conventional ones, which reduces the weight of the wheels. It also reduces torque measurement errors due to increased wheel weight as much as possible. Furthermore, it is possible to maintain the correct offset, making it possible to reduce the weight of the wheels accordingly. A torque measuring device capable of accurately measuring torque can be provided.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of the overall configuration of the torque measuring device according to the present invention, and FIG. 2 is a side view of the embodiment shown in FIG. 1, partially cut away. , Figure 3 shows the first
FIGS. 4 and 5 are front views showing the configuration of the detector with wheels omitted, and FIGS. 4 and 5 are views showing details of the configuration of the first strain plate. Figure 5 is A- in Figure 4.
A cross-sectional view in the direction of arrow A', FIG. 6, and FIG. 7 are diagrams showing the structure of the second strain plate in detail. -B' arrow direction sectional view, FIGS. 8 and 9 are enlarged sectional views showing the attached state of the strain gauge, with the first attachment scheduled surface and the second attachment scheduled surface shown in FIG. 5 being representative, respectively. , Figure 8 shows a strain gauge for torque detection, Figure 9 shows an example of a strain gauge for side force detection, and Figures 10 and 11 show a bridge for torque detection and a bridge for side force detection, respectively. The circuit diagram, FIG. 12 is an enlarged front view showing the vicinity of the torque bending piece in order to explain the torque detection operation, and FIG. The schematic diagram shown in FIG. 14 is an enlarged schematic diagram further enlarging a part of FIG. 13. 1... Drive shaft, 2... Caliper 13... Wheel, 3a.
...Rim, 4...Disc,
4a... Cutting part, 5... Mounting adapter,
6... Welded part, 7... First strain plate, 8... Second strain plate, 9.10, 11.12... Attachment Schedule, 13.
...Annular space, 1, 4. , ]-4a Communication hole, 15... Counterbore hole for hub bolt, 15a... Screw insertion hole, 16... Hole, 17... Terminal chamber, 18...・Terminal board, 18a
...terminal, 19...wiring groove,
20...Connection part, 21...Wire concentration space, 22...Wiring nail hole, 23...Outer cover, 23a...Insertion hole, 24...Inner cover , 25.27,27a, 30a... Bolt, 26...
・Detector, 28... Axis center, 29... Wheel center, 30... Gear, 29a...
Regular offset position, 31... Magnetic sensor, 32... Slip ring device, 37.4.8... Insertion hole, 38.39, 49.50... Annular groove, 40 .51...
...Strain mushroom forming hole, 4L 42, 43, 52, 53.54 ...Strain piece, 55...Mounting hole, 58...
Center, A1-A16. Bl~B1.6. C1~C16゜D1~D 1.6...Torque detection strain gauge,
E1-E16. Fl~Fi6. Gl～G16゜H1～H
16...Strain gauge for side force detection. Figure 13 Figure 14

Claims (2)

[Claims] (1) In a torque measuring device that converts and measures the torque acting on a wheel into an electrical quantity, there is a wheel with a large circular hole formed in the center of the disk, and a regular one that fits into the circular hole of this wheel. A mounting adapter is firmly fixed to the wheel while maintaining the same offset as the wheel, and the mounting adapter has a generally disk-like overall shape, is overlapped concentrically with the mounting adapter, and has at least four holes on the circumference of a predetermined radius. By uniformly forming a number of holes divisible by a first strain-generating plate formed to be larger than the minimum width and detachable from the drive shaft of the vehicle with a mounting bolt; A strain-generating piece under the same conditions as the first strain-generating plate is formed, and is superimposed concentrically with the first strain-generating plate, and is firmly fixed to the first strain-generating plate with bolts in the inner and outer vicinity of the strain-generating plate. A second strain plate fixed to the hole, and a first attachment surface on one side of the hole and a first attachment surface on the other side of the hole, which form a pair with a predetermined strain piece of the first and second strain plates in between. A strain gauge attached to each of the two surfaces to be attached is provided, and the strain gauge attached to the first surface to be attached, which is one of the pair, is attached to the two opposing first surfaces.
and the second bridge side, respectively, and the strain gauges attached to the second attachment surface forming the other of the pair are connected to the third and fourth bridge sides adjacent to the first and second bridge sides, respectively. A torque measuring device characterized in that a circuit is connected to each side of the bridge to form a Wheatstone bridge for torque detection. (2) Wheatstone Bridge is the first bridge of the pair.
Strain gauges attached to the surface to be attached and attached to half circumferences of the first and second strain plates are connected in circuits to the two opposing first and second bridge sides, respectively, for each half circumference, and Strain gauges attached to the second attached surface forming the other pair and attached to half circumferences of the first and second strain plates are attached to the first and second bridge sides, respectively, by half circumferences of the first and second strain plates. A torque measuring device characterized in that the torque measuring device is constructed by connecting circuits to adjacent third and fourth bridge sides, respectively.